离子膜电解阴极和阳极涂层

A good Cathode coating: 好的阴极涂层 Reduces hydrogen overvoltage by more than 200 mV over bare nickel. 相对于无涂层的镍，阴极涂层可降低氢过电位200mV以 上
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Importance of Coatings 涂层的重要性
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Importance of Coatings 涂层的重要性
A good Anode coating: 好的阳极涂层 Keeps your plant in business, with a very flat cell voltage profile over 8 years. 可在保证期八年时间内，维持平稳的电槽电压。
允许范围250~315 g/l 一般采用310 g/l
1 per 4 hours by operator in primary brine area 4小时一次，在一次盐水 1 per 8 hours shift, recorded automated data log
1 per 8-hour operator check to verify continuous Al reading with AAL/AAH
Manganese: Will cover existing DSA® catalyst with pseudo-catalytic coating which is almost impossible to remove. 锰：会覆盖掉阳极活性涂层，形成一层伪涂层，且几乎不可能除去 Barium/Strontium/Silica: Form tenacious deposits which are very difficult to remove.
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Causes of Cathode coating failure 阴极涂层的失效
High number of plant unprotected shut down: 过多的无保护停车
In presence of an high number of plant unprotected (no polarizator rectifier) shut downs there is a double effect: 过多的无保护停车（无极化整流器的投用），会造成： • Cathodic coating peel off due to reversal current phenomena. 反向电流造成阴极涂层脱落 • Coating deactivation and substrate corrosion due to Cl2 back migration from the anodic compartment. Cl2反向迁移到阴极室，造成阴极涂层失去活性及镍基体的腐蚀
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Recommended Brine Specs 推荐的盐水规格
Component or Impurity 成分 Allowable Level 允许范围 Analysis Frequency 分析频率
NaCl Concentration 盐水浓度 Temperature 温度
pH
310 gpl (Typical) 250~315 allowable
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How to maintain good coating performance all along the guaranteed life 在寿命保证期内，如何保持好的涂层性能
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How to maintain good coating performance all along the guaranteed life 在寿命保证期内，如何保持好的涂层性能
推荐的盐水规格（续）
Component 成分 Calcium plus Magnesium 钙+镁 Strontium 锶 Barium 钡 BaSO4 Na2SO4 Chlorates 氯酸盐 Allowable Level 允许范围 < 0.020 ppm < 0.40 ppm < 0.01 ppm < 0.01 ppm < 10 gpl < 14.0 gpl as ClO3Analysis Frequency 分析频率 1 per 8 hours by Lab (ICP) 1 per 24 hours of storage retention, by field operator 1 per day by Lab (ICP) 1 per day by Lab (ICP) 1 per day 1 per day 每天一次 每天一次
To maintain good anodic coating performance all along the guaranteed life is necessary to stress two main aspects of the plant operation: 要在寿命保证期内，保持好的阳极涂层性能，操作中必须注意两点： Brine Purity: 盐水质量 Apart from the impurities seen before, brine quality does not effect directly the coating life but the monitoring and good maintenance of all the brine purification section will avoid the loose of efficiency of the membrane that is among the primary reasons of early anodic coating deactivation. 除了上面提到的杂质，其它杂质不会直接影响到涂层寿命，但会 降低膜的效率。膜效率是影响阳极涂层寿命的基本因素之一
1 per week 每周一次
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Recommended Brine Specs (continued)
推荐的盐水规格（续）
Component 成分 SiO2 Aluminium Iron Nickel 铁 镍 铝 Allowable Level 允许范围 < 5.0 ppm < 0.10 ppm < 0.1 ppm < 0.003 ppm Analysis Frequency 分析频率 1 per week 每周一次 1 per week 每周一次 1 per week 每周一次 1 per week 每周一次 1 per week 每周一次 1 per month 每月一次 1 per month 每月一次
钡/锶/硅：会沉积在活性涂层表面，且很难除去
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Causes of Anode coating failure
阳极涂层失效的原因
Other possible reason of anode coating failure are: 其它可能导致阳极涂层失效的因素： Caustic back-migration: 碱的反向迁移 OH- ion back-migration through membrane scratch. OH-离子通过膜的划伤部位反向迁移
IEM Anode and Cathode Coating Operation
离子膜电解阴极和阳极涂层
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AGENDA 要讨论的话题
Importance of Coatings. 涂层的重要性 Causes of Coating Failure. 涂层失效的原因 How Maintain good coating performances all along the guaranteed life. 在寿命保证期内，如何保持好的涂层性能 Measuring the Residual coating load. 检测剩余的涂层 Measuring coating and membrane condition during the operation. 在电槽操作期间，检测涂层及膜的状况
A Bad Anode Coating: 坏的阳极涂层 Will cause a very sharp voltage increase in a short period of time up to the point where plant has to be shut down. 可在短时间内造成槽电压迅速上升，直至使电槽被迫停车 A Bad Cathode coating: 坏的阴极涂层 Will cause a quick increase of the cell voltage of about 100/150 mV: every 100 mV increase is equivalent to ~ 3% increase in power cost. 会导致槽电压快速上升100~150mV; 槽电压上升100mV, 电耗约增3%
8小时一次由操作工分析
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65oC ~ 80oC As required based on electrolyzer condition
Value as required for chlorine purity 2~11 allowable range
根据对氯气纯度的要求 允许范围2-11
Recommended Brine Specs (continued)
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How to maintain good coating performance all along the guaranteed life 在寿命保证期内，如何保持好的涂层性能

Baidu Nhomakorabea
Brine Purity: 盐水质量 Monitor and record any brine impurity excursions and do not over run the plant in presence of Ca, Mg, Sr and Ba pick. 监测并记录盐水中的杂质，不要让电槽在Ca、Mg、Ba、Sr 等杂质超标的情况下运行。
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Causes of Anode and Cathode Coating Failure
阴、阳极涂层失效的原因
Causes of Anode coating failure 阳极涂层失效的原因
Anode coating failure can be caused by some impurities present in the feed brine such as: 盐水中的一些杂质会导致阳极涂层失效 Fluoride: Parts per million levels in brine will strip the DSA® coatings to bare Ti in hours. 氟：盐水中ppm级的氟也会在数小时内使涂层脱落
OH- ion back-migration through membrane pin hole. OH-离子通过膜上的小孔反向迁移 Tear in the membrane. OH-离子通过撕裂的膜反向迁移 Normal coating ageing: 正常的涂层的老化
Occurs after years of anode service. 使用数年后，涂层会渐渐老化 Difficult to detect. 这种情况很难探测 Requires regeneration (recoating) of the substrate or mesh replacement. 必须进行重涂或换活性网
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Causes of Cathode coating failure 阴极涂层的失效
Cathode coating failure can be caused by:
阴极涂层的失效可能由下列原因造成： High Fe content in the catholyte: 阴极液中含铁太高 Fe deposition on the cathode will cause an over coating layer that reduces the cathode coating activity. Fe在阴极表面沉积形成覆盖层，会导致阴极活性降低